Body Proximity Sensing for RF Exposure-Compliant Power Control
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Solution Overview
Problem
User equipment faces challenges in maintaining radio frequency (RF) exposure compliance while optimizing transmission power levels, especially when a human target is in proximity to the antenna, as existing methods may lead to excessive RF exposure due to imperfect body proximity sensing.
Innovation Solution
Implementing a body proximity sensor (BPS) to adjust transmission power levels dynamically between high and low settings based on the Probability of Detection (Pd) and False Alarm Rate, ensuring compliance with regulatory RF exposure limits by optimizing transmission power differences (X1-X2) to maximize average transmission power gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transmission power is increased to transmit signals over greater distance and with less data loss, then communication performance is improved, but RF exposure to the user increases
Solution Approach 1:
The patent implements dynamic transmission power adjustment by transitioning from static power levels to adaptive power control. The system dynamically switches between high and low transmission power levels based on real-time body proximity sensor feedback, allowing communication performance to be optimized when safe while minimizing RF exposure when a body is detected near the antenna.
Solution Approach 2:
The patent employs a feedback mechanism where body proximity sensors continuously monitor the presence of a body near the antenna and provide real-time input to the transmission power control system. This feedback loop enables the system to automatically adjust transmission power levels in response to detected body proximity, resolving the contradiction between maintaining communication performance and limiting RF exposure.
2Object-affected harmful factors
If transmission power is limited to reduce RF exposure effect, then user safety is improved, but transmission distance and signal quality deteriorate
Solution Approach 1:
The system dynamically adjusts transmission power based on real-time conditions rather than using a fixed limited power level. When no body is detected in proximity, the system transitions to high transmission power mode, restoring transmission distance and signal quality while maintaining safety when a body is present.
Solution Approach 2:
The patent implements periodic monitoring of body proximity and corresponding periodic adjustment of transmission power levels. This allows the system to alternate between high and low power states based on the detected conditions, ensuring that transmission performance is maximized during safe periods while maintaining exposure limits when needed.
3Object-affected harmful factors
If body proximity sensing is used to adjust transmission power, then RF exposure compliance is improved, but device complexity increases due to additional sensors and control logic
Solution Approach 1:
The patent introduces body proximity sensors as intermediary components that mediate between the transmission power system and RF exposure concerns. These sensors provide indirect detection of body proximity conditions, enabling compliance with RF exposure regulations without requiring complex direct measurement and control systems.
Solution Approach 2:
The patent replaces complex mechanical or computational RF exposure measurement systems with simpler body proximity sensors. This substitution uses readily available sensor technology to achieve RF exposure compliance, significantly reducing the overall complexity of the control system while maintaining effectiveness.
4Productivity
If transmission power is dynamically adjusted based on body proximity detection, then average transmission power gain is maximized, but false alarm rate may reduce effective power optimization
Solution Approach 1:
The patent applies partial action by using moderate transmission power reductions when body proximity is detected, rather than complete power shutdown. This approach maintains some transmission capability even when a body is detected, optimizing average power gain while accounting for the possibility of false alarms. The system accepts some conservative power reduction to ensure reliability.
Solution Approach 2:
The patent adjusts the sensitivity parameters of the body proximity detection system to balance between detecting actual bodies and minimizing false alarms. By optimizing detection thresholds and response parameters, the system maximizes transmission power gain while maintaining acceptable false alarm rates, resolving the contradiction between productivity and reliability.
Data Source
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AI summary
A first transmission power level based on a radio frequency exposure limit and a second transmission power level based on the first transmission power level and a probability of detection of a body by a body proximity sensor are determined, where it is ensured that an average usage of the first and second transmission power levels over time does not exceed the transmission power limit, determined based on radio frequency exposure limits. A transmission power gain is determined based on a difference between the first and second transmission power level based on the probability of detection, and a false alarm rate of the body by the body proximity sensor. The transmission power gain may be used as a performance indicator to select from multiple first and second transmission power gains. First and second transmission power gains corresponding to the selected transmission power gain may be stored and applied during transmission.